help > Several questions for non-parametric stats and post-hoc
May 16, 2018  12:05 AM | Hyunwoo Kim
Several questions for non-parametric stats and post-hoc
Hi, CONN experts.

I'm doing 3 groups comparison using CONN.
I did F-test by contrast [1 -1 0; 0 1 -1] and got some significant area.(seed-to-voxel analysis & 2nd level analysis).

Statistic settings are below as CONN default gives;
 - height threshold p<0.001(p-uncorrected), cluster threshold p<0.05(cluster-size p-FDR corrected)
 - non-parametric stats with permutations = 1000

1) How can I determine the number of permutation?
   Because I don't know much about statistics, I don't know how to decide the number of permutations.
When I changed p-uncorrected value from 0.001 to 0.0001, CONN gives permutation number as 10000 and significant result disappeared.
Is there relationship between uncorrected p and number of iteration?

2) Is post-hoc available in CONN? If so, how?
As I mentioned, I've got some significant result from F-test. So I want to know where the difference come from.
In my limited knowledge, post-hoc would give answer but I don't know how to do it. If it is available in CONN, even available not in GUI but in command, please show me the way.

Thank you.